package StudentMangeSystem;

import java.util.ArrayList;
import java.util.Scanner;

public class StudentSystem {
    public static void startStudentSystem() {
        ArrayList<Student> list = new ArrayList<>();
        loop:while (true) {
            System.out.println("-------------欢迎来到学生管理系统----------------");
            System.out.println("1：添加学生");
            System.out.println("2：删除学生");
            System.out.println("3：修改学生");
            System.out.println("4：查询学生");
            System.out.println("5：退出");
            System.out.println("请输入您的选择:");
            Scanner sc = new Scanner(System.in);
            String choose = sc.next();
            switch (choose) {
                case "1" -> addStudent(list);
                case "2" -> deleteStudent(list);
                case "3" -> updateStudent(list);
                case "4" -> queryStudent(list);
                case "5" -> {
                    System.out.println("退出");
                    break loop;
//                    System.exit(0);停止虚拟机运行
                }
                default -> System.out.println("没有选项");
            }
        }

    }
    //添加学生
    public static void addStudent( ArrayList<Student> list){
        Student s=new Student();
        Scanner sc = new Scanner(System.in);

        String id = null;
        while (true) {
            System.out.println("请输入学生id");
            id = sc.next();
            boolean flag=contains(list,id);
            if(flag){
                System.out.println("id已存在，请重新录入");
            }else{
                s.setId(id);
                break;
            }
        }

        System.out.println("请输入学生姓名");
        String name = sc.next();
        s.setName(name);

        System.out.println("请输入学生年龄");
        int age = sc.nextInt();
        s.setAge(age);

        System.out.println("请输入学生地址");
        String address = sc.next();
        s.setAddress(address);
        //把学生对象放在集合中
        list.add(s);
        System.out.println("学生信息添加成功");
    }

    //删除学生
    public static void deleteStudent( ArrayList<Student> list){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要删除的id");
        String id = sc.next();

        int index=getIndex(list,id);
        if(index>=0){
            list.remove(index);
            System.out.println("id为"+id+"的学生删除成功");
        }else{
            System.out.println("id不存在删除失败");
        }
    }

    //修改学生
    public static void updateStudent( ArrayList<Student> list){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要修改的id");
        String id = sc.next();

        int index=getIndex(list,id);
        if(index==-1){
            System.out.println("要修改的id"+id+"不存在，请重新输入");
            return;
        }

        Student stu = list.get(index);

        System.out.println("请输入修改学生的姓名");
        String newName = sc.next();
        stu.setName(newName);
        System.out.println("请输入修改学生的年龄");
        int newAge = sc.nextInt();
        stu.setAge(newAge);
        System.out.println("请输入修改学生的地址");
        String newAddress = sc.next();
        stu.setAddress(newAddress);

        System.out.println("学生信息修改成功");
    }

    //查询学生
    public static void queryStudent( ArrayList<Student> list){
        if(list.size()==0){
            System.out.println("当前无学生信息，请添加后再查询");
            return;
        }
        System.out.println("id\t姓名\t年龄\t家庭地址");
        for (int i = 0; i < list.size(); i++) {
            Student stu = list.get(i);
            System.out.println(stu.getId()+"\t"+stu.getName()+"\t"+stu.getAge()+"\t"+stu.getAddress());
        }
    }

    //判断id在集合是否存在
    public static boolean contains(ArrayList<Student> list, String id){
//        for (int i = 0; i < list.size(); i++) {
//            Student stu = list.get(i);
//            String sid=stu.getId();
//            if(sid.equals(id)){
//                return true;
//            }
//        }
//        return false;
        return getIndex(list,id)>=0;
    }

    //通过id获取索引
    public static int getIndex(ArrayList<Student> list, String id){
        for (int i = 0; i < list.size(); i++) {
            Student stu = list.get(i);
            String sid=stu.getId();
            if(sid.equals(id)){
                return i;
            }
        }
        return -1;
    }

}
